diff --git a/homeassistant/components/comfoconnect/__init__.py b/homeassistant/components/comfoconnect/__init__.py
index 9c9b4aad711..5ff34526cc0 100644
--- a/homeassistant/components/comfoconnect/__init__.py
+++ b/homeassistant/components/comfoconnect/__init__.py
@@ -31,8 +31,6 @@ DEFAULT_PIN = 0
 DEFAULT_TOKEN = "00000000000000000000000000000001"
 DEFAULT_USER_AGENT = "Home Assistant"
 
-DEVICE = None
-
 CONFIG_SCHEMA = vol.Schema(
     {
         DOMAIN: vol.Schema(
diff --git a/homeassistant/components/generic/const.py b/homeassistant/components/generic/const.py
index eb376909422..4fd600db381 100644
--- a/homeassistant/components/generic/const.py
+++ b/homeassistant/components/generic/const.py
@@ -9,8 +9,3 @@ CONF_STILL_IMAGE_URL = "still_image_url"
 CONF_STREAM_SOURCE = "stream_source"
 CONF_FRAMERATE = "framerate"
 GET_IMAGE_TIMEOUT = 10
-
-DEFAULT_USERNAME = None
-DEFAULT_PASSWORD = None
-DEFAULT_IMAGE_URL = None
-DEFAULT_STREAM_SOURCE = None
diff --git a/homeassistant/components/tellstick/__init__.py b/homeassistant/components/tellstick/__init__.py
index 1007867362a..42685f03e03 100644
--- a/homeassistant/components/tellstick/__init__.py
+++ b/homeassistant/components/tellstick/__init__.py
@@ -40,10 +40,6 @@ SIGNAL_TELLCORE_CALLBACK = "tellstick_callback"
 # calling concurrently.
 TELLSTICK_LOCK = threading.RLock()
 
-# A TellstickRegistry that keeps a map from tellcore_id to the corresponding
-# tellcore_device and HA device (entity).
-TELLCORE_REGISTRY = None
-
 CONFIG_SCHEMA = vol.Schema(
     {
         DOMAIN: vol.Schema(